1
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De Mel S, Goh J, Rashid MBMA, Zhang XY, Jaynes P, Liu X, Poon L, Chan E, Lee J, Chee YL, Koh LP, Tan LK, Soh TG, Yuen YC, Loi H, Ng S, Goh X, Tan D, Cheah DMZ, Pang WL, Huang D, Chan JY, Somasundaram N, Tang T, Lim ST, Ong CK, Chng W, Chow EK, Jeyasekharan AD. CLINICAL APPLICATION OF AN EX‐VIVO PLATFORM TO GUIDE THE CHOICE OF DRUG COMBINATIONS IN RELAPSED/REFRACTORY LYMPHOMA; A PROSPECTIVE STUDY. Hematol Oncol 2021. [DOI: 10.1002/hon.147_2880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- S De Mel
- National University Health System Department of Haematology‐Oncology National University Cancer Institute, Singapore Singapore Singapore
| | - J Goh
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | | | - X. Y Zhang
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - P Jaynes
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - X Liu
- National University Health System Department of Haematology‐Oncology National University Cancer Institute, Singapore Singapore Singapore
| | - L Poon
- National University Health System Department of Haematology‐Oncology National University Cancer Institute, Singapore Singapore Singapore
| | - E Chan
- National University Health System Department of Haematology‐Oncology National University Cancer Institute, Singapore Singapore Singapore
| | - J Lee
- National University Health System Department of Haematology‐Oncology National University Cancer Institute, Singapore Singapore Singapore
| | - Y. L Chee
- National University Health System Department of Haematology‐Oncology National University Cancer Institute, Singapore Singapore Singapore
| | - L. P Koh
- National University Health System Department of Haematology‐Oncology National University Cancer Institute, Singapore Singapore Singapore
| | - L. K Tan
- National University Hospital Department of Laboratory Medicine Singapore Singapore
| | - T. G Soh
- National University Hospital Department of Laboratory Medicine Singapore Singapore
| | - Y. C Yuen
- National University Health System Department of Pharmacy Singapore Singapore
| | - Hoi‐Y Loi
- National University Hospital Singapore Department of Diagnostic Imaging Singapore Singapore
| | - Siok‐B Ng
- National University of Singapore Department of Pathology Yong Loo Lin School of Medicine Singapore Singapore
| | - X Goh
- National University Hospital, Department of Otorhinolaryngology Singapore Singapore
| | - D Tan
- Mt Elizabeth Hospital, Dr Daryl Tan Clinic for Lymphoma, Myeloma and Blood Disorders Singapore Singapore
| | - D. M. Z Cheah
- National Cancer Centre Singapore Lymphoma Genomic Translational Research Laboratory Division of Cellular and Molecular Research Singapore Singapore
| | - W. L Pang
- National Cancer Centre Singapore Lymphoma Genomic Translational Research Laboratory Division of Cellular and Molecular Research Singapore Singapore
| | - D Huang
- National Cancer Centre Singapore Lymphoma Genomic Translational Research Laboratory Division of Cellular and Molecular Research Singapore Singapore
| | - J. Y Chan
- National Cancer Centre Singapore Division of Medical Oncology Singapore Singapore
| | - N Somasundaram
- National Cancer Centre Singapore Division of Medical Oncology Singapore Singapore
| | - T Tang
- National Cancer Centre Singapore Division of Medical Oncology Singapore Singapore
| | - S. T Lim
- National Cancer Centre Singapore Division of Medical Oncology Singapore Singapore
| | - C. K Ong
- National Cancer Centre Singapore Division of Cellular and Molecular Research Singapore Singapore
| | - W.‐J Chng
- National University Health System Department of Haematology‐Oncology National University Cancer Institute, Singapore Singapore Singapore
| | - E. K Chow
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - A. D Jeyasekharan
- National University Health System Department of Haematology‐Oncology National University Cancer Institute, Singapore Singapore Singapore
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Hoppe MM, Fan S, Jaynes P, Peng Y, Liu X, De Mel S, Poon L, Chan E, Lee J, Chee YL, Ong CK, Tang T, Lim ST, Chng WJ, Grigoropoulos NF, VanSchoiack A, Bertolazzi G, Ng S, Tripodo C, Jeyasekharan AD. DIGITAL SPATIAL PROFILING OF DIFFUSE LARGE B‐CELL LYMPHOMAS REVEALS STING AS AN IMMUNE‐RELATED DETERMINANT OF SURVIVAL AFTER R‐CHOP THERAPY. Hematol Oncol 2021. [DOI: 10.1002/hon.8_2880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- M. M Hoppe
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - S Fan
- National University of Singapore Department of Pathology Yong Loo Lin School of Medicine Singapore Singapore
| | - P Jaynes
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - Y Peng
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - X Liu
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - S De Mel
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - L Poon
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - E Chan
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - J Lee
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - Y. L Chee
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - C. K Ong
- National Cancer Centre Singapore Division of Cellular and Molecular Research Singapore Singapore
| | - T Tang
- National Cancer Centre Singapore Division of Medical Oncology Singapore Singapore
| | - S. T Lim
- National Cancer Centre Singapore Division of Medical Oncology Singapore Singapore
| | - W. J Chng
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - N. F Grigoropoulos
- Singapore General Hospital Department of Haematology Singapore Singapore
| | | | - G Bertolazzi
- University of Palermo Tumor Immunology Unit Palermo Italy
| | - Siok‐B Ng
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - C Tripodo
- University of Palermo Tumor Immunology Unit Palermo Italy
| | - A. D Jeyasekharan
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
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3
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Hoppe MM, Jaynes P, Fan S, Peng Y, Hoang PM, Liu X, De Mel S, Poon L, Chan E, Lee J, Chee YL, Ong CK, Tang T, Lim ST, Grigoropoulos NF, Tan S, Hue SS, Chang S, Chuang S, Li S, Khoury JD, Choi H, Farinha P, Mottok A, Scott DW, Chng W, Ng S, Tripodo C, Jeyasekharan AD. MYC, BCL2 AND BCL6 COEXPRESSION PATTERNS AT SINGLE‐CELL RESOLUTION RE‐DEFINE DOUBLE EXPRESSOR LYMPHOMAS. Hematol Oncol 2021. [DOI: 10.1002/hon.9_2880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- M. M Hoppe
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - P Jaynes
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - S Fan
- National University of Singapore Department of Pathology Yong Loo Lin School of Medicine Singapore Singapore
| | - Y Peng
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - P. M Hoang
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - X Liu
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - S De Mel
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - L Poon
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - E Chan
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - J Lee
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - Y. L Chee
- National University Health System Department of Haematology‐Oncology Singapore Singapore
| | - C. K Ong
- National Cancer Centre Singapore Division of Cellular and Molecular Research Singapore Singapore
| | - T Tang
- National Cancer Centre Singapore Division of Medical Oncology Singapore Singapore
| | - S. T Lim
- National Cancer Centre Singapore Division of Medical Oncology Singapore Singapore
| | - N. F Grigoropoulos
- Singapore General Hospital Department of Haematology Singapore Singapore
| | - S.‐Y Tan
- National University of Singapore Department of Pathology Yong Loo Lin School of Medicine Singapore Singapore
| | - S. S.‐S Hue
- National University of Singapore Department of Pathology Yong Loo Lin School of Medicine Singapore Singapore
| | - S.‐T Chang
- Chi‐Mei Medical Center Department of Pathology Tainan Taiwan
| | - S.‐S Chuang
- Chi‐Mei Medical Center Department of Pathology Tainan Taiwan
| | - S Li
- The University of Texas MD Anderson Cancer Center Department of Hematopathology, Division of Pathology and Laboratory Medicine Houston USA
| | - J. D Khoury
- The University of Texas MD Anderson Cancer Center Department of Hematopathology, Division of Pathology and Laboratory Medicine Houston USA
| | - H Choi
- National University of Singapore Department of Medicine, Yong Loo Lin School of Medicine Singapore Singapore
| | - P Farinha
- BC Cancer Research Centre Department of Lymphoid Cancer Research Vancouver Canada
| | - A Mottok
- University Medical Center and University of Ulm, Institute of Human Genetics Ulm Germany
| | - D. W Scott
- BC Cancer Research Centre Department of Lymphoid Cancer Research Vancouver Canada
| | - Wee‐J Chng
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - S.‐B Ng
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
| | - C Tripodo
- University of Palermo Tumor Immunology Unit Palermo Italy
| | - A. D Jeyasekharan
- National University of Singapore Cancer Science Institute of Singapore Singapore Singapore
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4
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Guan P, Wong SF, Lim JQ, Ng CCY, Soong PL, Sim CQX, Ong CK, Rajasegaran V, Myint SS, Lee JY, Tan HK, Iyer NG, Soo KC, Teh BT, Tay ABG. Mutational Signatures in Mandibular Ameloblastoma Correlate with Smoking. J Dent Res 2019; 98:652-658. [PMID: 30917298 DOI: 10.1177/0022034519837248] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Ameloblastoma is a rare tumor of odontogenic epithelium, the low incidence rate of which precludes statistical determination of its molecular characterizations. Despite recent genomic and transcriptomic profiling, the etiology of ameloblastomas remains poorly understood. Risk factors of ameloblastoma development are also largely unknown. Whole exome sequencing was performed on 11 mandibular ameloblastoma samples. We identified 2 convergent mutational signatures in ameloblastoma: 1) a signature found in multiple types of lung cancers with probable etiology of tobacco carcinogens (COSMIC signature 4) and 2) a signature present in gingivobuccal oral squamous cell carcinoma and correlated with tobacco-chewing habits (COSMIC signature 29). These mutational signatures highlight tobacco usage or related mutagens as one possible risk factor of ameloblastoma, since the association of BRAF mutations and smoking was demonstrated in multiple studies. In addition to BRAF hotspot mutations (V600E), we observed clear inter- and intratumor heterogeneities. Interestingly, prior to BRAF mutation, important genes regulating odontogenesis mutated (e.g., corepressor BCOR), possibly playing important roles in tumorigenesis. Furthermore, recurrent mutations in the CDC73 gene, the germline mutations of which predispose patients to the development of jaw tumors, were found in 2 patients, which may lead to recurrence if not targeted by therapeutic drugs. Our unbiased profiling of coding regions of ameloblastoma genomes provides insights to the possible etiology of mandibular ameloblastoma and highlights potential disease risk factors for screening and prevention, especially for Asian patients. Because of the limited sample size and incomplete habitual, dietary, and occupational data, a causal link between tobacco usage and ameloblastoma still requires further investigations.
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Affiliation(s)
- P Guan
- 1 Integrated Biostatistics and Bioinformatics Programme, Duke-NUS Medical School, Singapore.,2 Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore.,3 Centre for Computational Biology, Duke-NUS Medical School, Singapore
| | - S F Wong
- 2 Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore
| | - J Q Lim
- 2 Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore.,4 Lymphoma Genomic Translational Research Laboratory, National Cancer Centre Singapore, Singapore
| | - C C Y Ng
- 2 Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore
| | - P L Soong
- 5 Department of Oral and Maxillofacial Surgery, National Dental Centre Singapore, Singapore
| | - C Q X Sim
- 5 Department of Oral and Maxillofacial Surgery, National Dental Centre Singapore, Singapore
| | - C K Ong
- 4 Lymphoma Genomic Translational Research Laboratory, National Cancer Centre Singapore, Singapore
| | - V Rajasegaran
- 2 Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore
| | - S S Myint
- 2 Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore
| | - J Y Lee
- 2 Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore
| | - H K Tan
- 6 Division of Surgical Oncology, National Cancer Centre Singapore, Singapore
| | - N G Iyer
- 6 Division of Surgical Oncology, National Cancer Centre Singapore, Singapore
| | - K C Soo
- 6 Division of Surgical Oncology, National Cancer Centre Singapore, Singapore
| | - B T Teh
- 2 Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore.,7 Cancer Science Institute of Singapore, National University of Singapore, Singapore.,8 Institute of Molecular and Cell Biology, Singapore.,9 Cancer and Stem Cell Biology Programme, Duke-NUS Medical School, Singapore.,10 SingHealth/Duke-NUS Institute of Precision Medicine, National Heart Centre Singapore, Singapore
| | - A B G Tay
- 5 Department of Oral and Maxillofacial Surgery, National Dental Centre Singapore, Singapore
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5
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Shahedah KK, How SH, Jamalludin AR, Mohd Faiz MT, Kuan YC, Ong CK. Depressive Symptoms in Newly Diagnosed Lung Carcinoma: Prevalence and Associated Risk Factors. Tuberc Respir Dis (Seoul) 2018; 82:217-226. [PMID: 30841021 PMCID: PMC6609524 DOI: 10.4046/trd.2018.0048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 07/14/2018] [Accepted: 10/16/2018] [Indexed: 01/07/2023] Open
Abstract
Background Depression is a recognized complication of lung cancer underreported in developing countries such as Malaysia. Treating and identifying depression in cancer patients increases survival and quality of life. Our objectives are to study prevalence of depressive symptoms in newly diagnosed lung carcinoma, and examine the relationship of depressive symptoms with other influencing risk factors. Methods A 2-year, cross sectional study February 2015–February 2017, was conducted at Hospital Tengku Ampuan Afzan, and Penang General Hospital. One hundred and three patients with newly diagnosed, biopsy confirmed primary lung carcinoma were recruited. Self-rated patient's identification sheet, validated Center for Epidemiologic Studies Depression (CES-D), and Dukes University Religion Index score from three different main languages were used. Results Prevalence of current depressive symptoms (CES-D total score ≥16) is 37.9%. The result suggests prevalence of those at high risk of moderate to major depression, may need treatment. Multivariate analysis reveals those with good Eastern Cooperation Oncology Group factor (η2=0.24, p<0.001) married (η2=0.14, p<0.001) with intrinsic religiosity (IR) (η2=0.07, p<0.02) are more resistant to depression. Conclusion One in three of lung carcinoma patients, are at increased risk for depression. Clinicians should be aware that risk is highest in those with poor performance status, single, and with poor IR. We suggest routine screening of depression symptoms as it is feasible, to be performed during a regular clinic visit with immediate referral to psychiatrist when indicated.
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Affiliation(s)
- K K Shahedah
- Department of Internal Medicine, Kulliyyah of Medicine, International Islamic University Malaysia (IIUM), Kuantan, Malaysia.
| | - S H How
- Department of Internal Medicine, Kulliyyah of Medicine, International Islamic University Malaysia (IIUM), Kuantan, Malaysia
| | - A R Jamalludin
- Department of Community Medicine, Kulliyyah of Medicine, International Islamic University Malaysia (IIUM), Kuantan, Malaysia
| | - M T Mohd Faiz
- Department of Psychiatry, Kulliyyah of Medicine, International Islamic University Malaysia (IIUM), Kuantan, Malaysia
| | - Y C Kuan
- Department of Internal Medicine, Kulliyyah of Medicine, International Islamic University Malaysia (IIUM), Kuantan, Malaysia
| | - C K Ong
- Department of Respiratory Medicine, Penang General Hospital, George Town, Malaysia
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6
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Nairismägi ML, Gerritsen ME, Li ZM, Wijaya GC, Chia BKH, Laurensia Y, Lim JQ, Yeoh KW, Yao XS, Pang WL, Bisconte A, Hill RJ, Bradshaw JM, Huang D, Song TLL, Ng CCY, Rajasegaran V, Tang T, Tang QQ, Xia XJ, Kang TB, Teh BT, Lim ST, Ong CK, Tan J. Oncogenic activation of JAK3-STAT signaling confers clinical sensitivity to PRN371, a novel selective and potent JAK3 inhibitor, in natural killer/T-cell lymphoma. Leukemia 2018; 32:1147-1156. [PMID: 29434279 PMCID: PMC5940653 DOI: 10.1038/s41375-017-0004-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 11/17/2017] [Accepted: 12/04/2017] [Indexed: 02/06/2023]
Abstract
Aberrant activation of the JAK3-STAT signaling pathway is a characteristic feature of many hematological malignancies. In particular, hyperactivity of this cascade has been observed in natural killer/T-cell lymphoma (NKTL) cases. Although the first-in-class JAK3 inhibitor tofacitinib blocks JAK3 activity in NKTL both in vitro and in vivo, its clinical utilization in cancer therapy has been limited by the pan-JAK inhibition activity. To improve the therapeutic efficacy of JAK3 inhibition in NKTL, we have developed a highly selective and durable JAK3 inhibitor PRN371 that potently inhibits JAK3 activity over the other JAK family members JAK1, JAK2, and TYK2. PRN371 effectively suppresses NKTL cell proliferation and induces apoptosis through abrogation of the JAK3-STAT signaling. Moreover, the activity of PRN371 has a more durable inhibition on JAK3 compared to tofacitinib in vitro, leading to significant tumor growth inhibition in a NKTL xenograft model harboring JAK3 activating mutation. These findings provide a novel therapeutic approach for the treatment of NKTL.
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Affiliation(s)
- M -L Nairismägi
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | | | - Z M Li
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - G C Wijaya
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - B K H Chia
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - Y Laurensia
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - J Q Lim
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - K W Yeoh
- Department of Radiation Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - X S Yao
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - W L Pang
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - A Bisconte
- Principia Biopharma, South San Francisco, CA, USA
| | - R J Hill
- Principia Biopharma, South San Francisco, CA, USA
| | - J M Bradshaw
- Principia Biopharma, South San Francisco, CA, USA
| | - D Huang
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - T L L Song
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - C C Y Ng
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - V Rajasegaran
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - T Tang
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - Q Q Tang
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - X J Xia
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - T B Kang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - B T Teh
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore.,Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - S T Lim
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore.,Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore.,Office of Education, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - C K Ong
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore. .,Genome Institute of Singapore, A*STAR, Singapore, Singapore.
| | - J Tan
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore. .,State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.
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7
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Loo YL, Wang HG, Zhang H, Ong CK. Miniaturized power limiter metasurface based on Fano-type resonance and Babinet principle. Opt Express 2016; 24:20816-20824. [PMID: 27607685 DOI: 10.1364/oe.24.020816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this work, we present a miniaturize power limiter, a device with size smaller than that required by the working frequency, made of coupled self-complementary electric inductive-capacitive (CELC) resonator and original electric inductive-capacitive (ELC) structure. We also make use of Babinet principle to ensure both CELC and ELC are resonating at the same frequency. The CELC structure is loaded with a Schottky diode to achieve the effect of a nonlinear power limiter. The constructive interference of CELC and ELC structure produces a new Fano-type resonance peak at a lower frequency. The Fano peak is sharp and able to concentrate electric field at a region between the inner and outer metallic patch of the metastructure, hence enhancing the nonlinear properties of the loaded diode. The Fano peak enhances the maximum isolation of the power limiter due to the local field enhancement at where the diode is loaded. Numerical simulation and experiment are conducted in the S-band frequency to verify the power limiting effect of the device designed and to discuss the formation of Fano peak. The power limiter designed has a maximum isolation of 8.4 dB and a 3-dB isolation bandwidth of 6%.
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8
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Nairismägi ML, Tan J, Lim JQ, Nagarajan S, Ng CCY, Rajasegaran V, Huang D, Lim WK, Laurensia Y, Wijaya GC, Li ZM, Cutcutache I, Pang WL, Thangaraju S, Ha J, Khoo LP, Chin ST, Dey S, Poore G, Tan LHC, Koh HKM, Sabai K, Rao HL, Chuah KL, Ho YH, Ng SB, Chuang SS, Zhang F, Liu YH, Pongpruttipan T, Ko YH, Cheah PL, Karim N, Chng WJ, Tang T, Tao M, Tay K, Farid M, Quek R, Rozen SG, Tan P, Teh BT, Lim ST, Tan SY, Ong CK. JAK-STAT and G-protein-coupled receptor signaling pathways are frequently altered in epitheliotropic intestinal T-cell lymphoma. Leukemia 2016; 30:1311-9. [PMID: 26854024 PMCID: PMC4895162 DOI: 10.1038/leu.2016.13] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 01/07/2016] [Accepted: 01/18/2016] [Indexed: 12/11/2022]
Abstract
Epitheliotropic intestinal T-cell lymphoma (EITL, also known as type II enteropathy-associated T-cell lymphoma) is an aggressive intestinal disease with poor prognosis and its molecular alterations have not been comprehensively characterized. We aimed to identify actionable easy-to-screen alterations that would allow better diagnostics and/or treatment of this deadly disease. By performing whole-exome sequencing of four EITL tumor-normal pairs, followed by amplicon deep sequencing of 42 tumor samples, frequent alterations of the JAK-STAT and G-protein-coupled receptor (GPCR) signaling pathways were discovered in a large portion of samples. Specifically, STAT5B was mutated in a remarkable 63% of cases, JAK3 in 35% and GNAI2 in 24%, with the majority occurring at known activating hotspots in key functional domains. Moreover, STAT5B locus carried copy-neutral loss of heterozygosity resulting in the duplication of the mutant copy, suggesting the importance of mutant STAT5B dosage for the development of EITL. Dysregulation of the JAK-STAT and GPCR pathways was also supported by gene expression profiling and further verified in patient tumor samples. In vitro overexpression of GNAI2 mutants led to the upregulation of pERK1/2, a member of MEK-ERK pathway. Notably, inhibitors of both JAK-STAT and MEK-ERK pathways effectively reduced viability of patient-derived primary EITL cells, indicating potential therapeutic strategies for this neoplasm with no effective treatment currently available.
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Affiliation(s)
- M-L Nairismägi
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - J Tan
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore.,Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - J Q Lim
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - S Nagarajan
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - C C Y Ng
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - V Rajasegaran
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - D Huang
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - W K Lim
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - Y Laurensia
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - G C Wijaya
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - Z M Li
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - I Cutcutache
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore.,Centre for Computational Biology, Duke-NUS Medical School, Singapore, Singapore
| | - W L Pang
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - S Thangaraju
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - J Ha
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - L P Khoo
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - S T Chin
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - S Dey
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - G Poore
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - L H C Tan
- Department of Pathology, Singapore General Hospital, Singapore, Singapore
| | - H K M Koh
- Advanced Molecular Pathology Laboratory, Singapore Health Services, Singapore, Singapore
| | - K Sabai
- Advanced Molecular Pathology Laboratory, Singapore Health Services, Singapore, Singapore
| | - H-L Rao
- Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - K L Chuah
- Department of Pathology, Tan Tock Seng Hospital, Singapore, Singapore
| | - Y-H Ho
- Department of Pathology, Tan Tock Seng Hospital, Singapore, Singapore
| | - S-B Ng
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore.,Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Pathology, National University Hospital, National University Health System, Singapore, Singapore
| | - S-S Chuang
- Department of Pathology, Chi Mei Medical Center, Tainan, Taiwan.,Department of Pathology, Taipei Medical University and National Taiwan University, Taipei, Taiwan
| | - F Zhang
- Department of Pathology, Guangdong General Hospital, Guangzhou, China
| | - Y-H Liu
- Department of Pathology, Guangdong General Hospital, Guangzhou, China
| | - T Pongpruttipan
- Department of Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Y H Ko
- Department of Pathology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - P-L Cheah
- Department of Pathology, University of Malaya, Kuala Lumpur, Malaysia
| | - N Karim
- Department of Pathology, Hospital Raja Permaisuri Bainun, Ipoh, Malaysia
| | - W-J Chng
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore.,Department of Haematology-Oncology, National University Hospital, National University Health System, Singapore, Singapore
| | - T Tang
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - M Tao
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - K Tay
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - M Farid
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - R Quek
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
| | - S G Rozen
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore.,Centre for Computational Biology, Duke-NUS Medical School, Singapore, Singapore
| | - P Tan
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore.,Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore.,Genome Institute of Singapore, A*STAR, Singapore, Singapore
| | - B T Teh
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore.,Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore.,Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore.,Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore
| | - S T Lim
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore.,Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore.,Office of Education, Duke-NUS Medical School, Singapore, Singapore
| | - S-Y Tan
- Department of Pathology, Singapore General Hospital, Singapore, Singapore.,Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Pathology, National University Hospital, National University Health System, Singapore, Singapore.,Department of Pathology, Guangdong General Hospital, Guangzhou, China.,Department of Pathology, University of Malaya, Kuala Lumpur, Malaysia.,Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore
| | - C K Ong
- Lymphoma Genomic Translational Research Laboratory, Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore
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9
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Kongpetch S, Puapairoj A, Ong CK, Senggunprai L, Prawan A, Kukongviriyapan U, Chan-On W, Siew EY, Khuntikeo N, Teh BT, Kukongviriyapan V. Haem oxygenase 1 expression is associated with prognosis in cholangiocarcinoma patients and with drug sensitivity in xenografted mice. Cell Prolif 2016; 49:90-101. [PMID: 26726846 DOI: 10.1111/cpr.12228] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 08/21/2015] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE Haem oxygenase-1 (HO-1) plays important roles in cytoprotection and tumour growth. Cholangiocarcinoma (CCA) is a deadly malignancy with very poor prognosis. The role of HO-1 in tumour progression in CCA up to now has been relatively unexplored, thus, its possible therapeutic implications in CCA have been investigated here. MATERIALS AND METHODS HO-1 expression in tumour tissues from 50 CCA patients was determined by immunohistochemical analysis and its association with survival time was evaluated using the Kaplan-Meier method. Its role in CCA cells in vitro was evaluated by transwell and wound healing assays and suppression of HO-1 expression by siRNA. Effects of HO-1 inhibition on gemicitabine (GEM)-mediated tumour suppression was evaluated in nude mice xenografted with CCA cells. RESULTS HO-1 expression was inversely associated with median overall survival time. Hazard ratio of patients with high HO-1 expression was 2.42 (95% CI: 1.16-5.08) with reference to low expression and HO-1 knock-down expression inhibited transwell cell migration. Suppression of HO-1 by Zn-protoporphyrin (ZnPP) enhanced cytotoxicity to GEM in CCA cells, validated in CCA xenografts. Treatment with GEM and ZnPP almost completely arrested tumour growth, whereas treatment with only a single reagent, retarded it. Tumour inhibition was associated with reduction in expression of Ki-67 and microvascular density, and enhanced p53 and p21 immunohistochemical staining. CONCLUSION High HO-1 expression was associated with poor prognosis of CCA. Synergistic role of HO-1 inhibition in chemotherapy of CCA is a promising insight for treatment of this tumour and warrants further investigation.
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Affiliation(s)
- S Kongpetch
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Liver Fluke and Cholangiocarcinoma Research Center, Khon Kaen University, Khon Kaen, Thailand
| | - A Puapairoj
- Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - C K Ong
- Laboratory of Cancer Epigenome, National Cancer Centre of Singapore, Singapore.,Division of Cancer and Stem Cell Biology, Duke-National University of Singapore Graduate Medical School, Singapore
| | - L Senggunprai
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Liver Fluke and Cholangiocarcinoma Research Center, Khon Kaen University, Khon Kaen, Thailand
| | - A Prawan
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Liver Fluke and Cholangiocarcinoma Research Center, Khon Kaen University, Khon Kaen, Thailand
| | - U Kukongviriyapan
- Department of Physiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - W Chan-On
- Laboratory of Cancer Epigenome, National Cancer Centre of Singapore, Singapore
| | - E Y Siew
- Laboratory of Cancer Epigenome, National Cancer Centre of Singapore, Singapore.,Division of Cancer and Stem Cell Biology, Duke-National University of Singapore Graduate Medical School, Singapore
| | - N Khuntikeo
- Liver Fluke and Cholangiocarcinoma Research Center, Khon Kaen University, Khon Kaen, Thailand.,Department of Surgery, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - B T Teh
- Laboratory of Cancer Epigenome, National Cancer Centre of Singapore, Singapore.,Division of Cancer and Stem Cell Biology, Duke-National University of Singapore Graduate Medical School, Singapore.,Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - V Kukongviriyapan
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Liver Fluke and Cholangiocarcinoma Research Center, Khon Kaen University, Khon Kaen, Thailand
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10
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Soh WT, Peng B, Chai G, Ong CK. Note: electrical detection and quantification of Spin Rectification Effect enabled by shorted microstrip transmission line technique. Rev Sci Instrum 2014; 85:026109. [PMID: 24593409 DOI: 10.1063/1.4865122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We describe a shorted microstrip method for the sensitive quantification of Spin Rectification Effect (SRE). SRE for a Permalloy (Ni80Fe20) thin film strip sputtered onto SiO2 substrate is demonstrated. Our method obviates the need for simultaneous lithographic patterning of the sample and transmission line, therefore greatly simplifying the SRE measurement process. Such a shorted microstrip method can allow different contributions to SRE (anisotropic magnetoresistance, Hall effect, and anomalous Hall effect) to be simultaneously determined. Furthermore, SRE signals from unpatterned 50 nm thick Permalloy films of area dimensions 5 mm × 10 mm can even be detected.
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Affiliation(s)
- Wee Tee Soh
- Center for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551
| | - Bin Peng
- Center for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551
| | - Guozhi Chai
- Temasek Laboratories, National University of Singapore, 5A Engineering Drive 2, Singapore 117411
| | - C K Ong
- Center for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551
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11
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Liu Y, Mukhtar M, Ma Y, Ong CK. Transmutation of planar media singularities in a conformal cloak. J Opt Soc Am A Opt Image Sci Vis 2013; 30:2280-2285. [PMID: 24322926 DOI: 10.1364/josaa.30.002280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Invisibility cloaking based on optical transformation involves materials singularity at the branch cut points. Many interesting optical devices, such as the Eaton lens, also require planar media index singularities in their implementation. We show a method to transmute two singularities simultaneously into harmless topological defects formed by anisotropic permittivity and permeability tensors. Numerical simulation is performed to verify the functionality of the transmuted conformal cloak consisting of two kissing Maxwell fish eyes.
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12
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Poon SL, Pang ST, McPherson JR, Yu W, Huang KK, Guan P, Weng WH, Siew EY, Liu Y, Heng HL, Chong SC, Gan A, Tay ST, Lim WK, Cutcutache I, Huang D, Ler LD, Nairismagi ML, Lee MH, Chang YH, Yu KJ, Chan-on W, Li BK, Yuan YF, Qian CN, Ng KF, Wu CF, Hsu CL, Bunte RM, Stratton MR, Futreal PA, Sung WK, Chuang CK, Ong CK, Rozen SG, Tan P, Teh BT. Genome-Wide Mutational Signatures of Aristolochic Acid and Its Application as a Screening Tool. Sci Transl Med 2013; 5:197ra101. [DOI: 10.1126/scitranslmed.3006086] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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13
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Wang N, Ma Y, Huang R, Ong CK. Far field free-space measurement of three dimensional hole -in -Teflon invisibility cloak. Opt Express 2013; 21:5941-5948. [PMID: 23482162 DOI: 10.1364/oe.21.005941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In this paper, we report a fabrication of a three-dimensional (3D) carpet cloak that works for any polarization in free space. Two-dimensional (2D) conformal mapping is first employed and the 3D structure is generated by a rotation of the 2D cloak. The structure of the cloak is hole-in-dielectric. The triangular invisible region has a height of 36 mm (one third of the height of the whole device) and a width of 240 mm. The cloaking effect is examined in free space by measuring the scattering parameters. The results show our device has very good cloaking performance in a wide frequency range from 4 to 10 GHz.
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Affiliation(s)
- Ning Wang
- Center for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore 117524, Singapore.
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14
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Phuoc NN, Ong CK. Anomalous temperature dependence of magnetic anisotropy in gradient-composition sputterred thin films. Adv Mater 2013; 25:980-984. [PMID: 23124510 DOI: 10.1002/adma.201203995] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Indexed: 06/01/2023]
Abstract
An abnormal behavior of increasing magnetic anisotropy with temperature in magnetic thin films fabricated by a gradient-composition sputtering technique is observed and consistently confirmed by two independent measurements of static magnetic hysteresis loops and dynamic magnetic permeability spectra. This peculiar behavior is suggested to be due to the physical origin of stress-induced magnetic anisotropy.
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Affiliation(s)
- Nguyen N Phuoc
- Temasek Laboratories, National University of Singapore, 5A Engineering Drive 2, Singapore.
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15
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Chusorn P, Namwat N, Loilome W, Techasen A, Pairojkul C, Khuntikeo N, Dechakhamphu A, Talabnin C, Chan-On W, Ong CK, Teh BT, Yongvanit P. Overexpression of microRNA-21 regulating PDCD4 during tumorigenesis of liver fluke-associated cholangiocarcinoma contributes to tumor growth and metastasis. Tumour Biol 2013; 34:1579-88. [PMID: 23417858 DOI: 10.1007/s13277-013-0688-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Accepted: 02/03/2013] [Indexed: 12/17/2022] Open
Abstract
MicroRNA, an endogenous noncoding RNA modulating gene expression, is a key molecule that by its dysregulation plays roles in inflammatory-driven carcinogenesis. This study aimed to investigate the role of oncomiR miR-21 and its target, the programmed cell death 4 (PDCD4) in tumor growth and metastasis of the liver fluke Opisthorchis viverrini-associated cholangiocarcinoma (CCA). The expression levels of miR-21 and PDCD4 were analyzed using the TaqMan miRNA expression assay and immunohistochemistry in liver tissues of both O. viverrini plus N-nitrosodimethylamine (NDMA)-treated hamsters and human CCA samples (n=23 cases). The functional assay for miR-21 was performed in CCA cell lines by the anti-miR-21 and pre-miR-21 transfection procedures. The peak of miR-21 levels were reached at 2 (hyperplastic lesions) and 6 (CCA) months of the O. viverrini plus NDMA-induced group and had a reverse response with its target PDCD4 proteins. In human CCA, miR-21 was overexpressed in tumor tissues when compared with nontumor tissues (P=0.0034) and had a negative correlation with PDCD4 protein (P=0.026). It was also found that high expression of miR-21 was significantly correlated with shorter survival (P<0.05) and lymph node metastasis (P=0.037) of CCA patients. Transient transfection of pre-miR-21 reduced the PDCD4 level and resulted in an increase of M213 CCA cell growth and wound-induced migration ability. These results indicated that miR-21 plays a role in the carcinogenesis and metastasis of O. viverrini-associated CCA by suppressing the function of PDCD4. Modulation of aberrantly expressed miR-21 may be a useful strategy to inhibit tumor cell phenotypes or improve response to chemotherapy.
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Affiliation(s)
- P Chusorn
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
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16
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Ma Y, Liu Y, Lan L, Wu T, Jiang W, Ong CK, He S. First experimental demonstration of an isotropic electromagnetic cloak with strict conformal mapping. Sci Rep 2013; 3:2182. [PMID: 23851589 PMCID: PMC3711045 DOI: 10.1038/srep02182] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 06/25/2013] [Indexed: 11/08/2022] Open
Abstract
In the past years quasi-conformal mapping has been generally used to design broadband electromagnetic cloaks. However, this technique has some inherit practical limitations such as the lateral beam shift, rendering the device visible or difficult to hide a large object. In this work we circumvent these issues by using strict conformal mapping to build the first isotropic cloak. Microwave near-field measurement shows that our device (with dielectric constant larger than unity everywhere) has a very good cloaking performance and a broad frequency response. The present dielectric approach could be technically extended to the fabrication of other conformal devices at higher frequencies.
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Affiliation(s)
- Yungui Ma
- Centre for Optical and Electromagnetic Research, State Key Lab of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310058, China
- These authors contributed equally to this work
| | - Yichao Liu
- Centre for Optical and Electromagnetic Research, State Key Lab of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310058, China
- Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542
- These authors contributed equally to this work
| | - Lu Lan
- Centre for Optical and Electromagnetic Research, State Key Lab of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310058, China
| | - Tiantian Wu
- Centre for Optical and Electromagnetic Research, State Key Lab of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310058, China
| | - Wei Jiang
- Centre for Optical and Electromagnetic Research, State Key Lab of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310058, China
| | - C. K. Ong
- Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542
| | - Sailing He
- Centre for Optical and Electromagnetic Research, State Key Lab of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310058, China
- Department of Electromagnetic Engineering, School of Electrical Engineering, Royal Institute of Technology, S-100 44 Stockholm, Sweden
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17
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Ong CK, Tan WC, Chan LC, Abdul Razak M. Cutaneous side-effects of epidermal growth factor receptor-tyrosine kinase inhibitor (TKI) in the treatment of lung cancer: description and its management. Med J Malaysia 2012; 67:222-223. [PMID: 22822651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Epidermal growth factor receptor (EGFR)--tyrosine kinase inhibitors (TKI) like erlotinib and gefitinib have been approved as monotherapy for the treatment of patients with locally advanced or metastatic non small cell lung cancer (NSCLC) after failure of at least one prior chemotherapy regimen. The use of EGFR-TKI is associated with unique and dramatic dermatologic side effects. We report 2 patients with NSCLC developing a typical acneiform (papulo-pustular) eruption shortly after initiation of EGFR-TKI.
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Affiliation(s)
- C K Ong
- Department of Respiratory Medicine, Hospital Pulau Pinang, Penang, Malaysia.
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18
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Yang Y, Leng LY, Wang N, Ma Y, Ong CK. Electromagnetic field attractor made of gradient index metamaterials. J Opt Soc Am A Opt Image Sci Vis 2012; 29:473-475. [PMID: 22472823 DOI: 10.1364/josaa.29.000473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present a device that is designed with varying permittivity ε(r) such that an electromagnetic wave in the K-band of the microwave regime entering it will bend inward towards the core. The core is made of silicon composites. We follow the distribution formula of the permittivity for the device derived by Narimanov and Kildishev using the optical-mechanical analogy. The diameter of the device is 14 cm, and it is constructed out of 21 rings of two different types of etched printed circuit boards, as well as dielectric powders as adding filling materials. The experimental wave intensity profile, based on parallel plate measurements for the cases where the incident plane wave is slightly displaced to the top of the center of the device and the case of on center incidence, are presented and discussed. In spite of some mismatch of the core and metamaterial structures of the device found, approximately 80% of the wave still manages to reach the core of the device and gets trapped and absorbed. Broadband properties of the device are also investigated.
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Affiliation(s)
- Yarong Yang
- Center for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore, Singapore
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19
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Ma YG, Lan L, Zhong SM, Ong CK. Experimental demonstration of subwavelength domino plasmon devices for compact high-frequency circuit. Opt Express 2011; 19:21189-21198. [PMID: 22108970 DOI: 10.1364/oe.19.021189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In optical frequency, surface plasmons of metal provide us a prominent way to build compact photonic devices or circuits with non-diffraction limit. It is attributed by their extraordinary electromagnetic confining effect. But in the counterpart of lower frequencies, plasmonics behavior of metal is screened by eddy current induced in a certain skin depth. To amend this, spoof plasmons engineered by artificial structures have been introduced to mimic surface plasmons in these frequencies. But it is less useful for practical application due to their weak field confinement as manifested by large field decaying length in the upper dielectric space. Recently, a new type of engineered plasmons, domino plasmon was theoretically proposed to produce unusual field confinement and waveguiding capabilities that make them very attractive for ultra-compact device applications [Opt. Exp. 18, 754-764 (2010)]. In this work, we implemented these ideas and built three waveguiding devices based on domino plasmons. Their strong capabilities to produce versatile and ultra-compact devices with multiple electromagnetic functions have been experimentally verified in microwaves. And that can be extended to THz regime to pave the way for a new class of integrated wave circuits.
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Affiliation(s)
- Y G Ma
- Center for Optical and Electromagnetic Research, State Key Lab of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310058, China.
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20
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Hung LT, Phuoc NN, Wang XC, Ong CK. Temperature dependence dynamical permeability characterization of magnetic thin film using near-field microwave microscopy. Rev Sci Instrum 2011; 82:084701. [PMID: 21895260 DOI: 10.1063/1.3622850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A temperature dependence characterization system of microwave permeability of magnetic thin film up to 5 GHz in the temperature range from room temperature up to 423 K is designed and fabricated as a prototype measurement fixture. It is based on the near field microwave microscopy technique (NFMM). The scaling coefficient of the fixture can be determined by (i) calibrating the NFMM with a standard sample whose permeability is known; (ii) by calibrating the NFMM with an established dynamic permeability measurement technique such as shorted microstrip transmission line perturbation method; (iii) adjusting the real part of the complex permeability at low frequency to fit the value of initial permeability. The algorithms for calculating the complex permeability of magnetic thin films are analyzed. A 100 nm thick FeTaN thin film deposited on Si substrate by sputtering method is characterized using the fixture. The room temperature permeability results of the FeTaN film agree well with results obtained from the established short-circuited microstrip perturbation method. Temperature dependence permeability results fit well with the Landau-Lifshitz-Gilbert equation. The temperature dependence of the static magnetic anisotropy H(K)(sta), the dynamic magnetic anisotropy H(K)(dyn), the rotational anisotropy H(rot), together with the effective damping coefficient α(eff), ferromagnetic resonance f(FMR), and frequency linewidth Δf of the thin film are investigated. These temperature dependent magnetic properties of the magnetic thin film are important to the high frequency applications of magnetic devices at high temperatures.
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Affiliation(s)
- Le Thanh Hung
- Center for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore
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21
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Teh BT, Varela I, Tarpey P, Raine K, Huang D, Ong CK, Furge KA, Campbell PJ, Stratton MR, Futreal PA. Identification of mutations of the SWI/SNF complex gene PBRM1 by exome sequencing in renal carcinoma. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.4571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Abstract
Perineural tumour spread refers to a contiguous neoplastic extension along a nerve. As it may be clinically silent, imaging plays a pivotal role in the evaluation and delineation of perineural infiltration in head and neck malignancies, which in turn affects treatment planning. This article focuses on the imaging features of perineural spread of head and neck tumours. The important potential perineural pathways and the possible underlying pathogenesis of this phenomenon are also reviewed.
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Affiliation(s)
- C K Ong
- Department of Diagnostic Imaging, National University Health System, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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23
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Chen L, Lin J, Chen HY, Xu S, Li K, Ong CK, Tan KL, Li J. CO adsorption and hydrogenation on crystalline YBa2Cu3Ox thin films. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19981020113] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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24
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Ma YG, Wang N, Ong CK. Application of inverse, strict conformal transformation to design waveguide devices. J Opt Soc Am A Opt Image Sci Vis 2010; 27:968-972. [PMID: 20448761 DOI: 10.1364/josaa.27.000968] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Integration of transformation optics with development of metamaterials offers great opportunities to create exotic material with electromagnetic functionality absent from nature. It has already led to several significant advancements in physical conceptions and technological applications such as invisible cloaking. Unfortunately practical application is often restricted by the complex requirements on material properties imposed by the general optical transformation theory. It is therefore necessary to relax the stringent requirements of materials properties in order to practicably use the power of transformation optics to design exotic optical devices. Development of new coordinate transformation mathematics to compromise between the stringent materials properties and the ultimate performance required by a useful novel device is required. In this work the authors employed strict conformal transformation to design physical materials that could guide light in a predetermined way. A simple and efficient numerical approach based on unusual inverse transformation is proposed here to quickly solve partial differential equations and construct the mapping relationship. The results showed that a transformed optical device could be made by purely using isotropic dielectric materials. Two application examples were numerically proposed to verify the versatility of conformal transformation and the robustness of the inverse approach. One was a 90 degrees waveguide beam bend, and the other was a waveguide-type beam splitter or coupler.
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Affiliation(s)
- Y G Ma
- Temasek Laboratories, National University of Singapore, Singapore 117411, Singapore.
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25
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Zhang XY, Wang XC, Xu F, Ma YG, Ong CK. High frequency dielectric properties distribution of BiFeO3 thin film using near-field microwave microscopy. Rev Sci Instrum 2009; 80:114701. [PMID: 19947745 DOI: 10.1063/1.3258201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A near-field scanning microwave microscopy (NSMM) is applied to investigate the local perpendicular dielectric information of single-phase multiferroic BiFeO(3) thin film and single crystal LaAlO(3) material. Our NSMM is composed of a vector network analyzer and a simple open-ended coaxial probe, which is quite different from the commercial probe with a lambda/4 coaxial resonator. The local permittivity is calculated quantitatively according to resonance frequency shift under the quasistatic microwave perturbation theory. We make use of the magnitude of reflection loss S(11) to construct an image reflecting the distribution of dielectric constant of a material. A homogeneous permittivity is observed in LaAlO(3) material and the inhomogeneous permittivity epsilon=215-250 for BiFeO(3) film is depicted from the change of feedback signal S(11) over an area of 100x100 microm(2).
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Affiliation(s)
- Xiao-Yu Zhang
- Temasek Laboratories, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore.
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Ma YG, Ong CK, Tyc T, Leonhardt U. An omnidirectional retroreflector based on the transmutation of dielectric singularities. Nat Mater 2009; 8:639-642. [PMID: 19561598 DOI: 10.1038/nmat2489] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Accepted: 05/27/2009] [Indexed: 05/28/2023]
Abstract
Transformation optics is a concept used in some metamaterials to guide light on a predetermined path. In this approach, the materials implement coordinate transformations on electromagnetic waves to create the illusion that the waves are propagating through a virtual space. Transforming space by appropriately designed materials makes devices possible that have been deemed impossible. In particular, transformation optics has led to the demonstration of invisibility cloaking for microwaves, surface plasmons and infrared light. Here, on the basis of transformation optics, we implement a microwave device that would normally require a dielectric singularity, an infinity in the refractive index. To fabricate such a device, we transmute a dielectric singularity in virtual space into a mere topological defect in a real metamaterial. In particular, we demonstrate an omnidirectional retroreflector, a device for faithfully reflecting images and for creating high visibility from all directions. Our method is robust, potentially broadband and could also be applied to visible light using similar techniques.
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Affiliation(s)
- Yun Gui Ma
- Temasek Laboratories, National University of Singapore, Singapore 119260, Singapore
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Li J, Chu HF, Zhang Y, Wang J, Zheng DN, Song Q, Wang P, Ma YG, Ong CK, Wang SJ. The role of magnetoelastic strain on orbital control and transport properties in an LaTiO(3)-CoFe(2)O(4) heterostructure. J Phys Condens Matter 2009; 21:276002. [PMID: 21828504 DOI: 10.1088/0953-8984/21/27/276002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Epitaxial heterostructures of CoFe(2)O(4)/LaTiO(3)/LaAlO(3) have been successfully prepared by using the pulsed laser deposition technique. The magnetoresistance (MR) of the samples is negative and linear with field at H≥2 T, exhibiting no dependence on field directions. Nevertheless, when H<2 T, the MR is negative in a field parallel to the sample plane, but positive in that along the film normal. This novel observed anisotropic MR is explained in terms of the magnetic anisotropy in the ferrimagnetic layer, as well as the magnetoelastic coupling between the two. In fields of different directions, the top CoFe(2)O(4) layer contracts or expands in the sample plane due to the significant magnetostriction effect, changing its resistance accordingly and exerting compressive or tensile strains on the bottom LaTiO(3) layer. Apparently the orbital status and the one-electron bandwidth in the LaTiO(3) layer are altered, which leads to a change in resistance.
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Affiliation(s)
- J Li
- National Laboratory for Superconductivity, Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
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Ong CK, Wang LL, Parkinson RJ, Wenderoth JD. Onyx embolisation of cavernous sinus dural arteriovenous fistula via direct percutaneous transorbital puncture. J Med Imaging Radiat Oncol 2009; 53:291-5. [DOI: 10.1111/j.1754-9485.2009.02086.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zhao L, Chen X, Ong CK. Visual observation and quantitative measurement of the microwave absorbing effect at X band. Rev Sci Instrum 2008; 79:124701. [PMID: 19123583 DOI: 10.1063/1.3043414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have set up a two-dimensional spatial field mapping system to measure graphically the quasi-free-space electromagnetic wave in a parallel plate waveguide. Our apparatus illustrates a potential application in characterizing the microwave absorbing materials. From the measured mappings of the microwave field, the visualization of spatial physical process and quantitative characterization of reflectivity coefficients can be achieved. This simple apparatus has a remarkable advantage over with conventional testing methods which usually involve huge, expensive anechoic chambers and demand samples of large size.
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Affiliation(s)
- L Zhao
- Department of Physics, Centre for Superconducting and Magnetic Materials, National University of Singapore, Singapore 117542, Singapore.
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Ma YG, Wang XC, Ong CK. Negative refractive index of metallic cross-I-shaped pairs: origin and evolution with pair gap width. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 78:016605. [PMID: 18764072 DOI: 10.1103/physreve.78.016605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Indexed: 05/26/2023]
Abstract
A structured composite of the negative index of refraction was fabricated by one layer of cross-I-shaped metal pairs. In this structure, the electric and magnetic inclusions were effectively integrated into one small unit. We varied the spacing of the cross pair to control the location of the magnetic resonance mode and their intercoupling with the electric mode. The frequency dependences of permittivity, permeability, and refractive indices with different gap widths of the pairs were systematically discussed by free-space measurement as well as numerical simulation. A spacing window dependent on the geometrical parameters was found in which the real part of the refractive index could have a negative value. The one-layer cross-pair pattern proposed in this work can be extended to three-dimensional structures with well-controlled interlayer coupling that will greatly facilitate the fabrication and measurement of negative-index materials in high frequencies.
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Affiliation(s)
- Y G Ma
- Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore 117542, Singapore.
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Ong CK, Lim SL, Tan WC, Ong EE, Goh AS. Endocrine complications in transfusion dependent thalassaemia in Penang Hospital. Med J Malaysia 2008; 63:109-112. [PMID: 18942294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Frequent blood transfusions can lead to iron overload which may result in several endocrine complications especially in the absence of adequate chelation therapy. The objectives of this study are to determine the prevalence of endocrine complications in transfusion dependent thalassaemia patients and the correlation of endocrine complications with the degree of iron chelation. This retrospective study looked at cases of adult patients with transfusion dependent thalassaemia treated in the Haematology Unit, Penang Hospital. Of the 25 transfusion dependent thalassaemia patients, there were 10 male and 15 female patients respectively with almost equal number of Malay and Chinese patients (13 and 12 patients respectively). Short stature was seen in 36.0% of our patients. In our cohort, 12 patients had delayed puberty (male 70.0% and female 33.3%). Prevalence of osteoporosis was 36.0%. Hypogonadism was noted in 40.0% of males and 46.7% of females. 53.4% of the female population had menstrual abnormalities with prevalence of primary and secondary amenorrhoea at 26.7% each. The prevalence of other endocrinopathies was much lower: 8.0% had diabetes mellitus and only one patient had hypocortisolism. Iron chelation appeared insufficient in our study population. The high frequency of endocrine complications noted in our study supports the rationale for regular follow-up of transfusion dependent thalassaemic patients to ensure early detection and timely treatment of associated complications.
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Affiliation(s)
- C K Ong
- Department of Medicine, Penang Hospital
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Abstract
Imaging plays an important role in the staging of nasopharyngeal carcinoma. Accurate staging is necessary, as the treatment is directly dependent on stage. Clinical examination provides information on mucosal involvement but is unable to determine the deep extension or the presence of skull base invasion or intracranial spread. The intent of this manuscript is to provide information of the specific imaging findings that will directly affect the stage and treatment of nasopharyngeal carcinoma as well as post-treatment complications.
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Affiliation(s)
- V F H Chong
- Department of Diagnostic Radiology, National University Hospital, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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Tan WC, Ong CK, Lo KSC, Leong KN. Pyoderma gangrenosum. Med J Malaysia 2007; 62:251-253. [PMID: 18246920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Pyoderma Gangrenosum (PG) is a non-infective, necrotising neutrophilic dermatosis. Many diseases may mimic PG. It may be idiopathic or may be associated with a systemic disorder. We report a case of PG in association with ulcerative colitis.
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Affiliation(s)
- W C Tan
- Department of Dermatology, Penang Hospital, Jalan Residensi, 10990, Penang
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Tan WC, Ong CK, Kang SCL, Razak MA. Two years review of cutaneous adverse drug reaction from first line anti-tuberculous drugs. Med J Malaysia 2007; 62:143-146. [PMID: 18705448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
First line Anti-TB therapy with rifampicin, isoniazid, pyrazinamide, and ethambutol/streptomycin is very effective. However, major adverse reactions to antituberculous drugs can cause significant morbidity and mortality. Cutaneous adverse drug reaction (CADR) is one of the commonly observed major adverse events. This retrospective study looked at the cases of TB treated in Respiratory Unit, Penang Hospital from January 2004 to December 2005. Of 820 patients treated for active TB, 47 patients (25 females; 22 males) developed CADR (5.7%). CADRs observed include morbiliform rash (72.3%), erythema multiforme syndrome (8.5%), urticaria (8.5%) and others (which include exfoliative dermatitis and lichenoid eruption). Ninety-seven percent of events occurred within two months after the initial dose. Incidence rate of CADR among the first line anti-TB drugs, pyrazinamide was the commonest offending drug (2.38%), followed by streptomycin (1.45%), ethambutol (1.44%), rifampicin (1.23%) and isoniazid (0.98%). Various clinical characteristics of patients with CADR identified include Human Immunodeficiency Virus (HIV) infection (27.7%), polypharmacy (21.3%), elderly (19.1%), autoimmune disorders (6.4%), pre-existing renal impairment (4.3%), pre-existing liver disorders (4.3%). In conclusion, CADR is common and majority of cases occurred within two months after initiation of anti-TB treatment, particularly in HIV infected patients. Pyrazinamide is the commonest offending drug.
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Affiliation(s)
- W C Tan
- Department of Dermatology, Penang Hospital, Penang
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Chan DBY, Ong CK, Soo RLK. Subdural empyema post-chemoradiotherapy for nasopharyngeal carcinoma. Singapore Med J 2006; 47:1089-91. [PMID: 17139409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Nasopharyngeal carcinoma is a common malignancy in the Asian Chinese population. The first-line treatment for Stage III/IV disease has in recent times shifted from radiotherapy to that of concurrent chemoradiotherapy. The treatment is not infrequently associated with in-field complications. We describe a rare case of one such complication -- subdural empyema developing post-chemoradiotherapy in a 56-year-old man with Stage IVB nasopharyngeal carcinoma.
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Affiliation(s)
- D B Y Chan
- Department of Haematology-Oncology, National University Hospital, Singapore.
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Abstract
Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide. OKL38 is a pregnancy-induced growth inhibitory gene and its expression is lost in various breast cancer cell lines and kidney tumor. To determine the role of OKL38 expression in HCC, we investigated its expression in various HCC samples and liver cancer cell lines. Western blot analysis revealed that OKL38 protein was absent or reduced in 64.2% (18 of 28) of the HCCs examined and four liver cancer cell lines. Immunohistochemistry study demonstrated that OKL38 protein was undetectable in 41.3% (38 of 92) of HCC, whereas 39.1% (36 of 92) of HCC showed low expression of the protein. Lost or reduced expression level of OKL38 protein was significantly correlated to high tumor stages in HCC (P=0.0042). Overexpression of the OKL38 caused cell death in Chang liver cells. 5' Untranslated region (5'UTR) deletion studies demonstrated that OKL38 was downregulated via translation suppression associated with the 5'UTR of its mRNA. Taken together, the 5'UTRs of OKL38 might play an important role in downregulation of its protein and the absence of OKL38 could lead to the development or progression of HCC.
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Affiliation(s)
- C K Ong
- Laboratory of Molecular Endocrinology, Division of Cellular and Molecular Research, National Cancer Centre of Singapore, Singapore, Singapore
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Leong CTC, Ong CK, Tay SK, Huynh H. Silencing expression of UO-44 (CUZD1) using small interfering RNA sensitizes human ovarian cancer cells to cisplatin in vitro. Oncogene 2006; 26:870-80. [PMID: 16862170 DOI: 10.1038/sj.onc.1209836] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ovarian cancer is currently the second leading cause of gynecological malignancy and cisplatin or cisplatin-based regimens have been the standard of care for the treatment of advance epithelial ovarian cancers. However, the efficacy of cisplatin treatment is often limited by the development of drug resistance either through the inhibition of apoptotic genes or activation of antiapoptotic genes. We have previously reported the overexpression of human UO-44 (HuUO-44) in ovarian cancers and the HuUO-44 antisera markedly inhibited NIH-OVCAR3 ovarian cancer cell attachment and proliferation (Oncogene 23: 5707-5718, 2004). In the present study, we observed through the cancer cell line profiling array that the expression of HuUO-44 was suppressed in the ovarian cancer cell line (SKOV-3) after treatment with several chemotherapeutic drugs. Similarly, this suppression in HuUO-44 expression was also correlated to the cisplatin sensitivity in two other ovarian cancer cell lines NIH-OVCAR3 and OV-90 in a dose-dependent manner. To elucidate the function of HuUO-44 in cisplatin chemoresistance in ovarian cancer cell, small interfering RNAs (siRNAs) were employed to mediate HuUO-44 silencing in ovarian cancer cell line, NIH-OVCAR3. HuUO-44 RNA interference (RNAi) resulted in the inhibition of cell growth and proliferation. Importantly, HuUO-44 RNAi significantly increased sensitivity of NIH-OVCAR3 to cytotoxic stress induced by cisplatin (P<0.01). Strikingly, we have also demonstrated that overexpression of HuUO-44 significantly conferred cisplatin resistance in NIH-OVCAR3 cells (P<0.05). Taken together, UO-44 is involved in conferring cisplatin resistance; the described HuUO-44-specific siRNA oligonucleotides that can potently silence HuUO-44 gene expression may prove to be valuable pretreatment targets for antitumor therapy or other pathological conditions that involves aberrant HuUO-44 expression.
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Affiliation(s)
- C T C Leong
- Laboratory of Molecular Endocrinology, Division of Cellular and Molecular Research, National Cancer Centre of Singapore, Singapore, Singapore
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Abstract
Dynamic renal scintigraphy is an established method in nuclear medicine, commonly used for the assessment of renal function. In this paper, a biphasic model fitting method is proposed for simultaneous estimation of both vascular and parenchymal parameters from renal scintigraphic data. These parameters include the renal plasma flow, vascular and parenchymal mean transit times, and the glomerular extraction rate. Monte Carlo simulation was used to evaluate the stability and confidence of the parameter estimates obtained by the proposed biphasic method, before applying the method on actual patient study cases to compare with the conventional fitting approach and other established renal indices. The various parameter estimates obtained using the proposed method were found to be consistent with the respective pathologies of the study cases. The renal plasma flow and extraction rate estimated by the proposed method were in good agreement with those previously obtained using dynamic computed tomography and magnetic resonance imaging.
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Affiliation(s)
- T S Koh
- Center for Modeling and Control of Complex Systems, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore
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Abstract
Abstract
The need to increase water productivity is a growing global concern as the World Commission on Water has estimated that demand for water will increase by c. 50% over the next 30 years and approximately half of the world's population will experience conditions of severe water stress by 2025. Three-quarters of African countries are expected to experience unstable water supplies, whereby small decreases in rainfall induce much larger reductions in streamflow. Vital water catchments have been lost or are being degraded, creating concerns about the loss of hydrological functions and increasing competition for scarce water resources between agriculture, urban centres, industry and wildlife. The challenge is to improve water productivity at the landscape or river basin level, especially for the rapidly growing populations in many developing countries. Water productivity is defined as the value or benefit derived from the use of water. In this review, we describe recent findings regarding the hydrology of forests and agroforestry systems and indicate how modifications to tree-based systems may increase water productivity in the semi-arid tropics. Throughout the tropics, reforestation using eucalyptus has been the most significant approach for modifying the water productivity of forestry and agroforestry systems. Fortunately, the 'eucalyptus dilemma' of providing local benefit at the expense of decreased streamflow for downstream users has been well articulated in many countries where evidence-based research has changed water policy and discouraged further planting of eucalyptus on water catchments. In East Africa, the most popular replacement for eucalyptus has been another exotic from Australia, Grevillea robusta, which has become the species of choice for farmers in the sub-humid highlands. However, attempts to introduce this species to semi-arid areas have been disappointing due to its evergreen canopy and consequently high demand for water. Current attempts to use deciduous species such as Melia volkensii and Paulownia fortunei in such areas are much more encouraging, although the long-term implications are still unknown. Agroforestry has the potential to improve water productivity in two ways. Trees can increase the quantity of water used on-farm for tree or crop transpiration and may also improve the productivity of the water that is used by increasing the biomass of trees or crops produced per unit of water used. Plot-level evidence shows that improvements in water productivity resulting from modifications to the microclimate experienced by crops may be limited. Instead, evidence from semi-arid areas of India and Kenya has shown that the greater productivity of agroforestry systems is primarily due to the greater quantity of water used. Further research is needed to examine the impact of the increased water use on drainage and base flow at the landscape level. Finally, we describe some of the technical approaches, which may be used to improve water productivity based on differences in tree phenology and the challenges facing smallholders in areas of growing water scarcity.
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Nguyen TH, Ong CK, Wong E, Leong CT, Panasci L, Huynh H. 2-Chloroethyl-3-sarcosinamide-1-nitrosourea (SarCNU) exhibits p53-dependent and -independent antiproliferative activity in human nasopharyngeal carcinoma cells in vitro and in vivo. Int J Oncol 2005; 27:1131-40. [PMID: 16142332 DOI: 10.3892/ijo.27.4.1131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
2-Chloroethyl-3-sarcosinamide-1-nitrosourea (SarCNU) has been used to treat patients with advanced solid tumours. However, the molecular mechanisms are not well understood. In the present study, we report that SarCNU inhibited proliferation of human HK-1 and CNE-2 nasopharyngeal carcinoma (NPC) in vivo and in vitro. In vitro study showed that wild-type p53 HK-1 cells were 3-fold more sensitive to SarCNU than p53 mutant CNE-2 cells. G2/M arrest, reduction in p21(Cip1/Waf1) and inactivation of cellular cdc-2 activity were seen in both SarCNU-treated HK-1 and CNE-2 cells. Upregulation of p53, phosphorylated p53 at Ser15 and biochemical markers for apoptosis, such as cleaved caspase-3, cleaved caspase-7 and cleaved PARP, were observed in SarCNU-treated HK-1 but not CNE-2 cells. The levels of cyclin B1, Wee1 and phosphorylated cdc-2 but not total cdc-2 in HK-1 cells were significantly reduced by SarCNU treatment. In contrast to HK-1 cells, decrease in total cdc-2 but increase in phosphorylated cdc-2 at Tyr15, cyclin B1 and Wee1 was observed in CNE-2 cells treated with SarCNU. Introduction of mutant p53 into HK-1 cells resulted in growth enhancement in vivo and increased resistance to SarCNU-induced apoptosis in vitro. Furthermore, CNE-2 cells transfected with wild-type p53 became susceptible to SarCNU-induced apoptosis in vitro but not their growth rate in vivo. The data indicate that in NPC cells SarCNU-induced apoptosis was p53-dependent while SarCNU-induced G2/M arrest was mediated by altering the levels of cyclin B1-cdc-2 complex and phosphorylation of cdc-2 at Tyr15 resulting in inactivation of cellular cdc-2 activity. Our data suggest a potential use of SarCNU in the treatment of NPC.
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Affiliation(s)
- T H Nguyen
- Laboratory of Molecular Endocrinology, Division of Cellular and Molecular Research, National Cancer Centre of Singapore, Singapore 169610
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Tan BJY, Sow CH, Koh TS, Chin KC, Wee ATS, Ong CK. Fabrication of Size-Tunable Gold Nanoparticles Array with Nanosphere Lithography, Reactive Ion Etching, and Thermal Annealing. J Phys Chem B 2005; 109:11100-9. [PMID: 16852354 DOI: 10.1021/jp045172n] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two-dimensional ordered arrays of gold (Au) nanoparticles were fabricated using two different variants of the nanosphere lithography technique. First, ordered arrays of polystyrene nanospheres on Si substrate were used as deposition masks through which gold films were deposited by electron beam evaporation. After the removal of the nanospheres, an array of triangular Au nanodisks was left on the Si substrate. After thermal annealing at increasing temperature, systematic shape transition of the nanostructures from original triangular Au nanodisks to rounded nanoparticles was observed. This approach allows us to systematically vary the size and morphology of the particles. In the second and novel technique, we made use of reactive ion etching to simultaneously reduce the dimension of the masking nanospheres and create arrays of nanopores on the substrate prior to the deposition of the Au films. These samples were subsequently annealed, which resulted in size-tunable and ordered Au nanoparticle arrays with the nanoparticles nested in the nanopores of the templated substrate. With the nanoparticles anchored in the nanopores, the substrate could be useful as a template for growth of other nanomaterials.
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Affiliation(s)
- B J Y Tan
- Department of Physics, Blk S12, Faculty of Science, National University of Singapore, 2 Science Drive 3, Singapore 117542, USA
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Abstract
The coercivity of magnetic thin film having a two-dimensional easy-axis distribution is investigated within the framework of a simple micromagnetic model. It is found that the coercivity decreases from 0.14H(K) to a minimum of 0.07H(K) as thickness increases, where H(K) is the anisotropy field. It is substantially lower than that given by the Stoner-Wohlfarth model and is consistent with available experimental data. The calculated hysteresis loop and the initial magnetization curve are also in good agreement with experiments.
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Affiliation(s)
- G P Zhao
- Institute of Solid State Physics, Sichuan Normal University, Chengdu, 610066, People's Republic of China
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Chen YW, Wang WC, Yu WH, Kang ET, Neoh KG, Vora RH, Ong CK, Chen LF. Ultra-low-? materials based on nanoporous fluorinated polyimide with well-defined pores via the RAFT-moderated graft polymerization process. ACTA ACUST UNITED AC 2004. [DOI: 10.1039/b315129h] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Rao XS, Ong CK. Subwavelength imaging by a left-handed material superlens. Phys Rev E Stat Nonlin Soft Matter Phys 2003; 68:067601. [PMID: 14754364 DOI: 10.1103/physreve.68.067601] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2003] [Indexed: 05/24/2023]
Abstract
In this work, a finite-difference time-domain (FDTD) method is employed to justify the superlensing effect of left-handed material (LHM) slabs. Our results demonstrate that subwavelength resolution can be achieved by LHM slabs with certain parameters. We present the dynamic feature of the imaging process and the dependence of physical parameters on the performance of the superlens. These results help to clarify the diverse FDTD results reported previously. We also show that the achievable resolution is limited by the absorption and thickness of the LHM slabs, which introduces difficulties in practical applications of the superlens.
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Affiliation(s)
- X S Rao
- Temasek Laboratories, National University of Singapore, Singapore 119260.
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Nguyen TTT, Tran E, Ong CK, Lee SK, Do PT, Huynh TT, Nguyen TH, Lee JJ, Tan Y, Ong CS, Huynh H. Kaempferol-induced growth inhibition and apoptosis in A549 lung cancer cells is mediated by activation of MEK-MAPK. J Cell Physiol 2003; 197:110-21. [PMID: 12942547 DOI: 10.1002/jcp.10340] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A vast variety of naturally occurring substances have been shown to protect against experimental carcinogenesis and an increasing amount of evidence suggests that kaempferol may have cancer chemopreventative properties. However, the precise underlying protective mechanisms are poorly understood. To elucidate these mechanisms, we challenged human lung cancer cell line A549 with kaempferol and investigated its effects upon cellular growth and signal transduction pathways. Treatment of A549 cells with kaempferol resulted in a dose- and time-dependent reduction in cell viability and DNA synthesis with the rate of apoptosis equivalent to 0.9+/-0.5, 5.2+/-1.5, 16.8+/-2.0, 25.4+/-2.6, and 37.8+/-4.5% on treatment with 0, 17.5, 35.0, 52.5, and 70.0 microM kaempferol, respectively. Concomitantly, kaempferol treatments led to a 1.2-, 2.7-, 3.3-, and 3.4-fold increase in Bax. Similar elevations were also observed in Bad which increased 1.2-, 3.3-, 3.7-, and 4.7-fold, respectively, as compared to control. Bcl-2 and Bcl-xL expression were inhibited in a dose-dependent fashion. While the Akt-1 and phosphorylated Akt-1 were inhibited, the mitogen-activated protein kinase (MAPK) was activated upon kaempferol treatment. Kaempferol induced apoptosis was associated with the cleavage of caspase-7 and poly ADP-ribose polymerase (PARP). Inhibition of MEK1/2 but not PI-3 kinase blocked kaempferol-induced cleavage of caspase-7, PARP cleavage, and apoptosis. The results suggest that inactivation of Akt-1 and alteration of Bcl-2 family of proteins are not sufficient for kaempferol to induce apoptosis and activation of MEK-MAPK is a requirement for kaempferol-induced cell death machinery in A549 cells.
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Affiliation(s)
- T T T Nguyen
- Laboratory of Molecular Endocrinology, Division of Cellular and Molecular Research, National Cancer Centre of Singapore, Singapore
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Zhan Q, Yu R, He LL, Li DX, Li J, Xu SY, Ong CK. Reversible structural transition in epitaxial manganite film. Phys Rev Lett 2002; 88:196104. [PMID: 12005649 DOI: 10.1103/physrevlett.88.196104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2001] [Indexed: 05/23/2023]
Abstract
A reversible structural transition of an epitaxial La(2/3)Sr(1/3)MnO3 film deposited on a LaAlO3 substrate has been investigated by means of in situ high-resolution transmission electron microscopy and electron diffraction, combined with image and diffraction calculations. We observe that the crystallographic symmetry of the film can be lowered via electron beam irradiation, leading to a rhombohedral-monoclinic transition. This transition can be attributed to the cooperating effect of the mismatch stress and the irradiation-induced thermal stress.
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Affiliation(s)
- Q Zhan
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China
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Ong CK, Joseph BK, Waters MJ, Symons AL. Growth hormone receptor and IGF-I receptor immunoreactivity during orthodontic tooth movement in the prednisolone-treated rat. Angle Orthod 2001; 71:486-93. [PMID: 11771788 DOI: 10.1043/0003-3219(2001)071<0486:ghraii>2.0.co;2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Bone remodeling during tooth movement is regulated by local and systemic factors. Two regulators of bone metabolism are growth hormone (GH) and insulin-like growth factor-I (IGF-I). Their effects are mediated via binding to GH receptor (GHR) and IGF-I receptor (IGF-IR) in target tissues. Corticosteroids may affect the activity of these growth factors. This study examined the effect of prednisolone on GHR and IGF-IR expression in dental tissues following orthodontic tooth movement. The corticosteroid-treated group (N = 6) was administered prednisolone (1 mg/kg) daily and the control group (N = 6) received equivalent volumes of saline. An orthodontic force (30 g) was applied to the maxillary first molar. Animals were sacrificed 12 days postappliance insertion. Sagittal sections of the first molar were stained for GHR and IGF-IR immunoreactivity. GHR and IGF-IR cell counts were elevated following appliance-treatment. Orthodontic tooth movement appeared to up-regulate GHR and IGF-IR immunoreactivity, but this up-regulation was reduced following prednisolone treatment. The suppression of GHR and IGF-I immunoreactivity in steroid-treated animals infers the mechanism whereby bone resorption and deposition, necessary for orthodontic tooth movement, may be inhibited by prednisolone. However, at 12 days postappliance insertion, no difference in orthodontic tooth movement was observed following low-dose prednisolone treatment.
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Affiliation(s)
- C K Ong
- School of Dentistry, The University of Queensland, Brisbane, Australia
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Abstract
Growth factors and growth inhibitors play crucial roles in the growth regulation and differentiation of mammary epithelial cells. Studies have shown that during pregnancy, with the onset of terminal differentiation, there is a dramatic decrease in the proliferation of the mammary epithelial cells. Here we report the cloning and characterization of a novel pregnancy-induced cDNA, OKL38, from a human ovarian cDNA library. This cDNA encodes for a protein of approximately 34.5 kDa. Tissue distribution studies through Northern analyses revealed the ubiquitous nature of OKL38 transcripts in most tissues, with the highest levels observed in the ovary, kidney, and liver. The onset and advancement of pregnancy also gave rise to a concomitant increase in OKL38 gene expression. In situ hybridization revealed that OKL38 mRNA was further detected in mammary secretory epithelial cells. However, low levels of OKL38 transcripts were observed in the various human breast cancer cell lines studied and were barely detectable in all dimethylbenz(A)anthracene-induced mammary tumors examined. Transfection studies with OKL38 cDNA with MCF-7 cells resulted in growth inhibition in vitro and reduction in tumor formation in vivo. These observations led to speculation that OKL38 may play a vital role in the growth regulation and differentiation of breast epithelial cells during pregnancy and its implications in tumorigenesis.
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Affiliation(s)
- H Huynh
- Laboratory of Molecular Endocrinology, Division of Cellular and Molecular Research National Cancer Center of Singapore, Singapore 169610.
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49
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Abstract
A complementary DNA, uterine-ovarian-specific gene 44 (UO-44), has been isolated from tamoxifen-induced rat uterine complementary DNA library using differential display techniques. UO-44 transcripts are found to be abundant in the uterus and ovary. UO-44 gene expression in the uterus is strictly regulated by estrogens, tamoxifen, and GH, whereas the pure antiestrogen ICI 182780 is inhibitory. Treatment of ovariectomized rats and hypophysectomized rats with tamoxifen and GH, respectively, resulted in up-regulation of UO-44 expression in a dose-dependent manner. In situ hybridization revealed that UO-44 gene expression was restricted to the luminal and glandular epithelial cells of the uterus and to granulosa cells of medium-size ovarian follicles. Transfection studies showed that UO-44 was a membrane-associated protein. Because estrogens, tamoxifen, and GH are stimulators of uterine luminal epithelial cell growth in vivo, UO-44 protein may serve as a mediator of the effect of these compounds in inducing epithelial proliferation and differentiation in these tissues.
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Affiliation(s)
- H Huynh
- Laboratory of Molecular Endocrinology, Division of Cellular and Molecular Research, National Cancer Centre of Singapore, Singapore 169610
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50
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Lim KB, Ng CY, Ong CK, Ong CS, Tran E, Nguyen TT, Chan GM, Huynh H. Induction of apoptosis in mammary gland by a pure anti-estrogen ICI 182780. Breast Cancer Res Treat 2001; 68:127-38. [PMID: 11688516 DOI: 10.1023/a:1011929222555] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The antiestrogen, ICI 182780 (ICI) proves to be clinically useful for the treatment of estrogen receptor positive breast tumours. We report the assessment of the in vivo and in vitro effects of ICI on apoptosis of breast epithelial cells. In vivo, administration of rats with ICI for 3 weeks resulted in a reduction in the size of the lobular structures with the rate of mammary epithelial apoptosis equivalent to 10, 35 and 45% on treatment with 1, 1.5 and 2 mg ICI per kg body weight, respectively. Concomitantly, these treatment led to a 2.0-, 2.2- and 2.5-fold increase in Bax. Similar elevations were also observed in Bad levels which increased 1.7-, 2.6- and 2.7-fold respectively in the ICI treatment as compared to controls. This also resulted in a dose dependent decrease in Bcl-2 and Bcl-xL protein expressions. Growth inhibition and induction of apoptosis were also observed in the MCF-7 cells following in vitro treatment with ICI. This is closely associated with [1] the down-regulation of Bcl-2 and Bcl-xL proteins and [2] upregulation of Bax and Bad, whose gene products are known to be involved the regulation of apoptosis in mammalian cells. Stable over-expression of Bcl-2 resulted in protection of MCF-7 cells from apoptosis and growth inhibitory effects of ICI. Conversely, reduction of Bcl-2 by antisense transfection make MCF-7 cells more sensitive to ICI-induced growth inhibition and apoptosis. These findings suggest that modulation of Bax, Bcl-xL, Bcl-2 and Bad proteins by ICI may be, in part, responsible for the anti-proliferative and apoptotic effect of ICI seen clinically and in animal models.
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Affiliation(s)
- K B Lim
- Division of Cellular and Molecular Research, National Cancer Centre of Singapore, Singapore
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